(() => {
    interface IPerson {
      firstName: string;
      lastName: string;
    }

    class Person{
        firstName:string
        lastName:string
        fullName:string
        constructor(firstName:string,lastName:string){
            this.firstName = firstName
            this.lastName = lastName
            this.fullName = this.firstName+this.lastName
        }
    }

   


  
    function showFullName(person: IPerson) {
      return person.firstName + "_" + person.lastName;
    }

    const person = new Person('诸葛','孔明')

    console.log(showFullName(person))
  })();
  